Reinforcing-bar.



D. B. LUTEN.

BEINFOBGING BAR. nrucruoi mum JULY 26, 1911.

Patented Aug. 19, 1913.

WITNESSES ATTORNEY.

projections another andwith such elevation b above the DANIEL 1B. LUTEN, OF

IN DIANAPOLIS, INDIAN ra'rnis'r carton..

REINFOBGIN'GBAB.

Original application filed April 29, 1981, Serial No. 57,951.

Specification of Letters Patent.

Divided and this application filed July 26,

1911. Serial No. $40,712.

T 0 all whom it may concern Be it known that I, DANIEb B. LU'rEN, a citizen of the United States. residing at Indianapolis, in the county of Marion and State of Indiana, have invented a new and useful Improvement in Reinforcing-Bars, of-which the following is-a specification.

My invention relatcs to improvements in reinforced concrete and has for its purpose to provide reinforcing bar with corrugatlons such that a maximum of tensile resistance may be developed in the embedded bar, with minimum materials and cost.

This application is a division of an application filed by me on April 29, 1901, Serial No. 57,951.

My invention is illustrated in the accompanying drawing representing a longitudinal section through bar of my improved yp The reinforcing barlO is provided with ll spaced at intervals 01. from one surface of the bar, that with unit width of bar, the shearing strength of the thickness a of the embedding concrete between projections will be greater-than the crushing strength oftheiheight Dot such concrete immediately adjacent tl'e torWard-faceof the projection. When suclra bar is embedded in concrete, subsequently thoroughly hardened,

and the bar subjected to tension tending to make it slip longitudinally through the occur by the projec-.

concrete, failure will tions crushiugthe concrete bearing against them. If however the. shearing strength through dimension .0 were less than the crushing strength of dimension. then the bar would have an excess of strength against crushing and failure would occur by shearing 0d of the concrete between projeti'onson lines parallel to the axis of the bar. ailure'of the latter kind would be much more serious than that of the former, be cause shearing of all the concrete between projections Would occur simultaneously so as to result in a. sudden release of timber throughout its length. if failure occurs by crushing at each'tace oil the projections, there will be only yielding of the bar at the instant that the concrete gives Way under the pressure of the face of the projection, and this crushing effect immediately powders the -i ncrete di- On the other hand a slight rectly in front or the projection so as to distribute the load radially against, the surrounding uncrushed concrete, thus producing an immediate increase of bearing area at each projection on the solid concrete, and of increased density of material at the immediate surface of contact. Hence the bar, in stead of pulling out clean, will but make a start toward failure hen it is immediately arrested until greater tension is applied. It is there-tore important be spaced so far apart that failure will occur by crushing rather than by shearing. If the projection is of uniform height. across the bar, this relation which is expressed by height of projection to distance between projections must be less than crushingstrength to shearing strength. Now the crushing strength of concrete isapproximately 2,000 lbs. per sq. inch, and the shearing strength about 200 lbs. per sq. inch. Hence the projections should be spaced apart apprcx'r matcly more than 10 times their height.

conformed to this requirement, but have the projections close together. "As a consequence tests have shown them to fail suddenly by shearing a hole through the concrete su ficient to permit the passage of the bar and its projections. Moreover Waste results; because more metal 'isrequired' to space the corrugations close together where j fore waste and ineiiicicncy go hand in hand. i on the contrary in my arrangement of corrugations at distances more than ten times their height metal is saved and efiiciency and safety increased.

I claim l. A reinforcing bar forconcrete, provided with projections of such height and spacing that the space between adjacent projections is more than ten times the height of the projections.

2. A reinforcing bar for concrete, pro

vided with projections of such height and height of the project'ons than that of the Patented A.ug.19,'1913.'

that the projections material crushing strength to the shearing strength l i .1 l yspacing that thespace between two adjal of concrete.

E 3. A reinforcement for hardened plastic l comprising a longitudinal member provided l with projections of such height and spacinp i that the shearing area of embedding hardened plastic between two adjacent, proji ctilons bears a ratio to the bearing area nine hundred and eleven. 0 t 'e rear projectiongreater than the ratio Q I of crushing strength to shearing strength I DANIEL N' 5 of the embedding hardened plastic. Witnesses:

In witness whereof, I have hereunto set- MAY LAYDEN, t my hand and sea] at Indianapolis, Indiana, .FRANK A. FAHLE.

this 20th day of July, A. D. one thousand 

